JPH06162626A - Recording/reproducing apparatus - Google Patents

Abstract

PURPOSE:To quickly detect buckling or riding of a tape over a flange of a guide post by detecting by an optical means the bend of a tape edge caused when the flange of a tape guide regulates an end part of the tape. CONSTITUTION:A photoelectric conversion photodetector 9 is set at such a position that the incident light upon the photodetector 9 from a light emitting element 6 is shut when a tape 16 buckles. The bend of the tape is detected by a combination of the elements 6 and the photodetector 9. When an upper end or a lower end of the tape is bent, it is detected as a photodetector 10 or 11 detectors light. At this time, when the photodetector 9 detects light, the tape is judged as normal. If the photodetector 9 does not detect light, it is judged as abnormal. When neither the photodetector 9, nor the photodetector 10 detects light, an upper edge of the tape is detected to be bent. If the photodetector 9 does not detect light, nor the photodetector 11 detects light, a lower edge of the tape is detected to be bent. When the photodetectors 10, 11 detect light while the photodetector 9 does not detect light, the tape is detected to be wrinkled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head of a video tape recorder for recording information on or reproducing information from a tape, and a tape stretched between two reels for recording and reproduction by the head. The present invention relates to a recording / reproducing apparatus having a tape guide means for forming a tape running path on a tape, and in particular, for a mechanism having a tape guide for restricting the tape running in the width direction, running by bending the tape end in the tape guide portion. The present invention relates to a transport mechanism that restores an abnormality to normal traveling.

[0002]

2. Description of the Related Art For example, Japanese Laid-Open Patent Publication No. 1-290149 discloses detection of a bending of a tape in a tape transport mechanism of a magnetic recording / reproducing apparatus. A pressure sensitive element is provided on a tape guide flange to detect a force applied to the flange, and the detection is performed. There is a disclosure of a technique in which the tape edge bending is changed by changing the inclination angle of the tape guide so that the value does not become larger than a predetermined value. However, since the purpose of the flange is to regulate the tape, it is inevitable that the regulation force will be applied, and it is difficult to determine what is abnormal because the proper regulation force varies depending on the tape thickness.

Further, in JP-A-60-57559, light for detecting tape deformation is projected on a running tape, and reflected light or transmitted light thereof is introduced as a detection signal to generate a vibration signal according to wavy deformation of the tape. DISCLOSURE OF THE TECHNOLOGY OF TAPE TRAVEL MONITORING APPARATUS FOR DETERMINING TAPE TRAVEL ABNORMALITY BY DETECTING WAVE DEFORMATION FROM CHANGE IN FREQUENCY OF OUTPUT SIGNAL, USING OUTPUT PHOTOELECTRIC CONVERSION RECEIVING DEVICE, AND DETECTING WRIGHTS OR BRIGHTS FROM CHANGE IN AMPLITUDE There is.

Further, in Japanese Unexamined Patent Publication No. Sho 62-205561, a width end surface of a magnetic tape is provided with a light source arranged to face one surface of the magnetic tape and a light receiver arranged to face the other surface. There is a disclosure of a technique for detecting the amount of light passing from the outside to measure the magnetic tape position from the change in the output.

[0005]

In a tape guide device of a magnetic recording / reproducing apparatus having a tape feeding mechanism such as a video tape recorder, particularly in a guide immediately before and after a rotary drum, a tape is provided on a lead spirally provided on a cylinder. Therefore, the regulation of the tape by the flange tends to become stronger because the Further, even when the guides before and after the rotary drum are inclined guides, a vertical force acts on the tape, so that the restriction force at the flange becomes large. When the tape is run in such a state, the tape tension increases due to the friction between the tape end portion and the flange, and when the thin tape is run, buckling may occur. Buckling is likely to occur when the tension applied to the tape is high and the tape is given a slow speed change, for example, when the user uses the variable speed reproduction function. An object of the present invention is to quickly detect the buckling or the tape running on the flange of the guide post and restore the tape to normal running.

[0006]

According to the prior art, in order to accurately determine the tape running position, it was necessary to accurately capture the output change of the sensor. However, considering that the running height of the tape is regulated by the flange of the guide post, it detects whether the tape width is less than the original width, or whether the tape floats above a certain height with respect to the guide surface. If you do so, you can see the buckling of the tape and the rise of the guide post to the flange. Therefore, the buckling of the tape can be detected by a binary judgment as to whether or not there is an input to the photoelectric conversion light receiving element. Further, since it is not necessary to detect the amplitude change or the frequency change for the abnormality detection, the processing of the output from the photoelectric conversion light receiving element becomes simple. According to the present invention, on two guide posts having flanges for tape end regulation having a large tape winding angle immediately before and after the rotating drum where tape edge breakage is most likely to occur in a tape running system of a magnetic recording / reproducing apparatus having a tape transport mechanism. Alternatively, a tape edge breakage detecting device composed of one or more sets of light emitting elements and photoelectric conversion light receiving elements is installed at two positions before and after the rotary drum in the tape running path to detect the tape edge breakage. For processing after detecting an abnormality, a method of stopping the traveling to protect the tape, a method of changing the inclination angle of the guide post to reduce the tension of the tape regulation part, and sucking the tape to the guide surface to drive the guide itself up and down There is a method to drive the tape and a method to drive the tape on the side opposite to the regulated end by vibrating the guide surface, but the cause of the tape edge breakage is the high tape tension and the slow speed when the user uses the variable speed playback. Since the speed change is such that the tape tension is lowered once the drive is stopped after detection, edge breakage is often eliminated naturally, and the tape is driven again at the set speed immediately before stop and the target speed is reached quickly at maximum acceleration. By doing so, it is possible to avoid a gradual speed change, so that it is possible to return to a normal running state very easily. When the edge break is detected again by the re-driving, the operation is stopped and re-driving again and the operation is repeated a plurality of times, preferably 3 times in total.
If normal tape running cannot be obtained after repeating up to twice, it is judged that recovery is impossible because there is some abnormality in the tape or running system, and a means to stop running and stop running trial to protect the tape. To take.

[0007]

With the above structure, the bending of the tape edge, which is likely to occur in the flange portion of the tape guide post immediately before and after the rotary drum installed in the tape running path of the magnetic recording / reproducing apparatus having the tape transport mechanism, is detected. ,
After the detection, the tape is stopped and re-driven, and if the bending of the tape edge is not improved, the operation of stopping and re-driving is repeated a plurality of times, preferably a total of three times. Alternatively, since there is some abnormality in the running system, it is judged that the recovery is impossible and the tape running can be stopped to protect the tape.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, and shows a guide post having rollers arranged on the inlet side and the outlet side of the rotary drum in the tape running system of FIG. By installing three sets of light emitting elements and photoelectric conversion light receiving elements in combination with this post, it is possible to detect a tape edge break. 1 is an upper flange that regulates the upper height in the tape width direction, 2 is a lower flange that regulates the lower height in the tape width direction, 3 is a guide roller that rotates as the tape runs, 4 is a fixed shaft, 5 Is a member for installing a light emitting element and a photoelectric conversion light receiving element, 6, 7 and 8 are light emitting elements,
Reference numerals 9, 10, and 11 denote photoelectric conversion light-receiving elements, which are surrounded by a light-shielding plate so that light does not enter the device, or are arranged in front of the photoelectric conversion light-receiving element so as to receive only light incident on the photoelectric conversion light-receiving element from the light-emitting element. A cylinder is installed in the section to block light coming in from other than the light emitting element section. 15 is a bearing, 16 is a tape,
31 is a rotary drum, 32 is a tape supply reel, 33 is a tape take-up reel, 34 is a capstan shaft, 41 is a tape input side, 42 is a tape output side, S1, S2, S6, T
1, T2, and T6 are fixed posts, S3, S4, S
7, S8, S10, T3, T4, T7, T8, and T
9 is a guide roller post, S5 and T5 are inclined posts, and S9 is a tension pin. There are two types of tape bending, namely, I mode in which the tape rides on the flange and buckles, and II mode in which the tape is buckled by being caught at the flange end. When the tape is buckled, the photoelectric conversion light receiving element is installed at a position where the incident light from the light emitting element 6 to the photoelectric conversion light receiving element 9 is shielded by the tape, thereby detecting the bending of the tape. And a combination of photoelectric conversion light receiving elements. Whether the tape edge bending has occurred at the upper end or the lower end is determined by which of the photoelectric conversion light receiving elements 10 or 11 receives light. Describing along the flow of the processing of FIG. 3, when 9 receives light, it is determined as normal, when 9 does not receive, it is determined as abnormal, and when 9 does not receive and 10 does not receive, it is determined that the upper edge of the tape is broken. However, 9 does not receive light and 1
When 1 does not receive the light, it is determined that the tape bottom edge is broken, and when 9 does not receive the light and both 10 and 11 receive the light, it is determined that the tape is wrinkled. In addition,
When light is received by 9, 10, and 11, it is determined that the transparent leader tape at the end of the tape has been detected. FIG. 4A shows a state in which a light emitting element or a photoelectric conversion light receiving element installed on a shaft is installed by another method. Light enters the light receiving element from the opening through the mirror or the opening through the mirror. The light emitting element or the photoelectric conversion light receiving element can be installed outside the guide post.

FIG. 5 is a diagram showing a second embodiment of the present invention. The figure shows a guide post having rollers arranged on the inlet side and the outlet side of the rotary drum in the tape running system shown in FIG.
The light emitting element and the photoelectric conversion light receiving element are configured by a mounting method different from that shown in FIG. 12 is a photoelectric conversion light receiving element 9
, 13 is an opening of the photoelectric conversion light receiving element 10, W is a tape width, H is an interval between upper and lower flanges, Hd1 is a distance from an inner end of the lower flange to an upper end of the opening of the photoelectric conversion light receiving element 9 and an inner end of the lower flange. It is assumed that the diameter of the beam projected from the light emitting element 6 to the photoelectric conversion light receiving element 9 is larger than the light receiving portion of the photoelectric conversion light receiving element at the distance from the light source to the light source of the light emitting element 6. Hd2 is photoelectric conversion light receiving element 1 from the inner end of the lower flange
The diameter of the beam projected from the light emitting element 7 to the photoelectric conversion light receiving element 10 is larger than the light receiving portion of the photoelectric conversion light receiving element 10 at the distance to the lower end of the opening of 0 and the distance from the inner end of the lower flange to the light source of the light emitting element 7. And Here, Hd1 and Hd2
Are each

[0010]

[Formula 1] Hd1 = W Hd2 = H−W (Formula 1) FIG. 6 shows an enlarged view of the opening. Reference numeral 17 denotes light projected from the light emitting element to the opening of the photoelectric conversion light receiving element.
The distance between the openings is so small that the photoelectric conversion light receiving element can always receive the light regardless of the position where the guide roller rotates and the photoelectric conversion light receiving element receives the light up to both ends of the opening. There is sufficient vertical size. Explaining according to the processing flow of FIG. 7, 9 receives light and 1
When 0 is not received, the distance from the inner end of the lower flange to the upper end of the tape is W or less, and therefore it is determined that the tape bending has occurred at the lower flange of the tape guide. When 9 receives light and 10 receives, it is determined that the tape end has been detected. When 9 does not receive the light and 10 receives the light, the distance from the inner end of the upper flange to the lower end of the tape is W or less, and therefore it is determined that the tape edge bending has occurred at the tape guide upper flange. The entire device should be surrounded by a light-shielding plate to prevent light from entering, or a tube should be installed in front of the photoelectric conversion light receiving element so that it receives only the light that enters the photoelectric conversion light receiving element from the light emitting element. Make a hole in the shaft and install it in the back to block light entering from other than the light emitting element part. Further, the positions of the light emitting element and the photoelectric conversion light receiving element may be interchanged and installed. Also, 1
Any light source having a spread enough to receive 9 or 10 when the tape is not on the post can be used as the light source. Further, if it is known that the tape edge bending occurs only in one of the upper flange and the lower flange, it is possible to detect only one by installing a pair of the light emitting element and the photoelectric conversion light receiving element. That is, the light receiving unit 9 and the light source may be installed to detect the edge bending at the upper flange, and the light receiving unit 10 and the light source may be installed to detect the tape edge bending at the lower flange. As described above, the edge breakage can be dealt with quickly by detecting the tape edge breakage at the portion of the guide post where the tape edge breakage occurs. FIG. 4B shows a state in which the light emitting element or the photoelectric conversion light receiving element installed on the shaft is installed by another method. Light enters the light receiving element from the opening through the mirror or the opening through the mirror. The light emitting element or the photoelectric conversion light receiving element can be installed outside the guide post.

FIG. 8 is a diagram showing a third embodiment of the present invention.
3 is a guide post having rollers arranged on the inlet side and the outlet side of the rotary drum in the tape running system shown in FIG. 2. W is the tape width, H is the distance between the upper and lower flanges, Hd1 is the distance from the inner end of the lower flange to the upper end of the opening 12, and Hd2 is the distance from the inner end of the lower flange to the lower end of the opening 13. Where Hd1 and Hd2 are

[0012]

Hd1 = W Hd2 = H−W (Equation 2) The light output from the light emitting element 6 passes through the opening 12 and is reflected by the tape 16, and the reflected light is input to the photoelectric conversion light receiving element 9. Similarly, the light output from the light emitting element 7 passes through the opening 13 and is reflected by the tape 16, and the reflected light is input to the photoelectric conversion light receiving element 10. When a tape edge breaks in the tape, the width of the tape becomes shorter than it should be.Therefore, the output from the light emitting element installed at the end opposite to the end where the edge break occurs is not reflected by the tape but leaks to the outside. The incident light on the photoelectric conversion light receiving element is reduced. Also, when the tape buckles on the flange end, the tape hanging on the opening on the buckled side floats and the direction of the reflective surface of the tape changes, so a certain amount of reflected light is incident on the photoelectric conversion light receiving element. do not do. Therefore 9 and 10
The time-integrated value of the amount of light received by each light-receiving element is calculated to obtain the average amount of received light, and when one or both of the average amounts of received light is less than a certain value, it is determined that a tape edge break has occurred. The entire device should be surrounded by a light-shielding plate to prevent light from entering, or a tube should be installed in front of the photoelectric conversion light receiving element so that it receives only the light that enters the photoelectric conversion light receiving element from the light emitting element. Make a hole in the shaft and install it in the back to block light entering from other than the light emitting element. The photoelectric conversion light receiving element and the light emitting element may be directly installed on the shaft, or may be installed by the method of FIG.

FIG. 9 is a diagram showing a fourth embodiment of the present invention, which is a tape edge bending detection device provided in the traveling path between the guide posts on the inlet side and the outlet side of the rotary drum in FIG. 14 is a member for installing a photoelectric conversion light receiving element, and 5
Alternatively, one of 14 is fixedly installed, and the other is moved according to the tape loading operation and installed at an appropriate position.
h1 is the lower limit of the tape by the flange regulation, h2 is the tape movable range by the flange regulation, W is the tape width, Hd1 is the height from the reference plane of the upper photoelectric conversion light receiving element opening surface and the height from the reference plane to the center of the light source 9. Hd2 is the height from the reference surface of the lower photoelectric conversion light receiving element opening surface and the height from the reference surface to the center of the light source 10, and the light emitted from the light source to the light receiving element is larger than the light receiving surface. Hd1 and Hd2 are represented by the following equations.

[0014]

## EQU00003 ## Hd1 = h1 + W Hd2 = h1 + h2-W (Equation 3) Explaining along the flow of processing in FIG. 7, when the photoelectric conversion light receiving element 9 receives light and 10 does not receive light, at the inner end of the lower flange. Judge that an edge bend has occurred.
When the photoelectric conversion light receiving element 9 receives light and 10 receives light, it is determined that a wrinkle or a transparent portion at the end of the tape is detected. When the photoelectric conversion light receiving element 9 does not receive light and 10 receives light, it is determined that the tape edge bending has occurred at the inner end of the upper flange. When the photoelectric conversion light receiving element 9 does not receive light and the photoelectric conversion light receiving element 10 does not receive light, it is determined that normal traveling is detected.

FIG. 10 shows a fifth embodiment of the present invention, which is a tape edge bend detecting device provided in the traveling path between the guide posts on the inlet side and the outlet side of the rotary drum in FIG. Reference numeral 19 is a member for installing the light emitting element 6, the photoelectric conversion light receiving elements 9 and 10, and 18 is a shield provided to shield ambient light other than incident light from 6 and openings provided for 9 and 10. Other than the incident light from the parts 12 and 13, it is blocked.

HL1 is the height to the top of the light emitting element, HL
2 is the height to the bottom of the light emitting element, X1 is the horizontal distance from the light emitting element installation portion to the tape, X2 is the horizontal distance from the tape to the opening of the shield, and X3 is the photoelectric conversion light receiving element from the opening of the shield. To Hd1, Hd1 is the height of the upper end of the opening 12, Hd2 is the height of the lower end of the opening 13, Hc1 is the height of the light receiving surface of the light receiving element 9, and Hc2 is the height of the light receiving surface of the light receiving element 10. . Hd1, Hd2, Hc1 and Hc2 are X
1, X2, X3, h1, h2, W, HL1, HL2 are represented by the following formulas.

[0017]

## EQU00004 ## Hd1 = (-X2.HL1 + (X1 + X2). (H1 + W)) / X1 Hd2 = (-X2.HL2 + (X1 + X2). (H1 + h2-W)) / X1 Hc1 = (X3 / (X1 + X2) +1) * Hd1-X3 / (X1 + X2) * HL1 Hc2 = (X3 / (X1 + X2) +1) * Hd2-X3 / (X1 + X2) * HL2 ... (Equation 4) The process flow is shown in FIG. A certain sampling time ts
The output of the photoelectric conversion light receiving elements 9 and 10 is checked for each light receiving element 9
When there is an input from the light emitting element, Va = Vah is output, and when there is no input, Va = VaL is output. When the light receiving element 10 receives an input from the light emitting element, Vb =
Vbh is output, and when there is no input, Vb = VbL is output. Here, Vah> VaL and Vbh> VbL. This operation is repeated a certain number of times kc, and during that time, the cumulative value Sa of Va and the cumulative value Sb of Vb are taken, and the average value Aa of the output of the light receiving element 9 is obtained from Sa and kc, and the average value of the output of the light receiving element 10 from Sb and kc. Ab is calculated and Aa is a certain value V
When Sa is smaller than sa and Ab is smaller than a certain value Vsb, Sa and Sb are set to 0 and this operation is repeated. If Aa is smaller than a certain value Vsa and Ab is larger than a certain value Vsb, it is determined that the tape is an upper edge break. When Aa is larger than a certain value Vsa and Ab is smaller than a certain value Vsb, it is determined that the tape bottom edge is broken. When Aa is larger than a certain value Vsa and Ab is larger than a certain value Vsb, it is determined that a transparent leader tape at the tape end is detected. Assuming that the number of times kc is kc = T / ts · N from the cycle T of the fundamental frequency component of the tape vibration, when N = 1, the ratio Ra of the period during which the light receiving element 9 has an input during one cycle is

[0018]

## EQU00005 ## Ra = (Sa-VaL.kc) / (Vah.kc-VaL.kc) ... (Equation 5) Here, ts is sufficiently smaller than the period T. Further, even if the period T is not accurately obtained, the accuracy of Ra that is obtained is increased if N is large. From this, for Ra instead of Aa, the edge breakage detection may be performed by determining the ratio of the input period during one cycle which becomes a threshold in place of Vsa. Similarly, the ratio Rb of the time during which there is an input from the light emitting element to the light receiving element 10 during the period T can be considered. The above-mentioned processing may be applied to the fourth embodiment. FIG. 12 shows a processing flow of the tape drive device after detecting the tape edge bending shown in the first to fifth embodiments. It is a figure. Hereinafter, description will be given along the flowchart of FIG. When the tape edge bending is detected, the tape set speed at that time and the running state such as recording and reproducing are stored, and the tape driving device such as the reel motor and the capstan motor is stopped. Then, the tape is re-driven at the previously stored speed and running condition. If tape edge bending is detected again within 5 seconds after re-driving,
The set speed and running condition are stored again and the tape drive is stopped. If the tape edge breakage is not improved by repeating the operation of re-driving and stopping three times in total, leave the tape in the stopped state to protect it and set the tape in the unloading state to indicate the tape maladaptation as a beep sound. Notify the user by

The tape edge breakage detecting method and the processing after the detection have been described above for the video tape recorder, but the configuration and processing method of the tape edge breakage detecting apparatus is the same as the magnetic recording / reproducing apparatus having another tape transport mechanism. Or
The present invention is also applicable to a recording / reproducing device that uses a tape such as light or paper as a recording medium.

[0020]

According to the present invention, the tape edge breakage caused by the regulation of the tape end portion of the flange of the tape guide is detected by the optical means, and the tape edge breakage is eliminated, and the tape is again driven and returned to the normal running state. If not, the tape can be protected by stopping running.

[Brief description of drawings]

FIG. 1 is a side view of a tape edge breakage detecting device installed in a tape guide showing a first embodiment.

FIG. 2 is an explanatory diagram of a tape running system.

FIG. 3 is a flowchart for explaining the first embodiment.

FIG. 4A is an explanatory diagram of an example of a light emitting element or light receiving element installation method in the first embodiment, and FIG. 4B is an explanatory diagram of an example of a light receiving element installation method in the second or third embodiment.

FIG. 5 is a perspective view of a tape edge breakage detecting device installed in a tape guide showing a second embodiment.

FIG. 6 is an explanatory diagram showing an opening of a tape guide post.

FIG. 7 is a flowchart for explaining the second and fourth embodiments.

FIG. 8 is a perspective view of a tape edge breakage detecting device installed in a tape guide showing a third embodiment.

FIG. 9 is a perspective view of a tape edge breakage detection device installed between tape guide posts according to a fourth embodiment.

FIG. 10 is a perspective view of a tape edge breakage detecting device installed between tape guide posts according to a fifth embodiment.

FIG. 11 is a flowchart for explaining a fifth embodiment.

FIG. 12 is a flowchart showing processing after detection of a tape edge break.

[Explanation of symbols] 1 ... upper flange, 2 ... lower flange, 3 ... guide roller,
4 ... Fixed shaft, 5 ... Light emitting element and photoelectric conversion light receiving element installation member, 6, 7, 8 ... Light emitting element, 9, 10, 11
Photoelectric conversion light receiving element, 12 ... Opening portion of photoelectric conversion light receiving element 9, 13 ... Opening portion of photoelectric conversion light receiving element 10, 14 ... Member for installing photoelectric conversion light receiving element, 15 ... Bearing, 16 ... Tape.

Claims (1)

[Claims] 1. A head for recording information on a tape or reproducing information from the tape, and a tape extending between two reels for guiding the tape to form a running path of the tape for recording and reproduction. In a recording / reproducing apparatus equipped with a tape guide means, it is possible to receive light from a light emitting element installed on a surface facing each other via a tape on both end flanges installed on the tape guide means, and light from the light emitting element. Photoelectric conversion light receiving element installed at a position,
A recording / reproducing apparatus comprising means for detecting a tape edge break from the output of the photoelectric conversion light receiving element.